Crossing protective system



July 4 19390 J. M, EVANS CROSS INC: PROTEGTIVE SYSTEM Filed 061;..2Q,1936 9 Sheets-Sheet 2 guy 14.?

INVENTOR.

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A TTORNEYS.

July 4, 1939.

J. M. EVANS CROSSING PROTECTIVE SYSTEM Filed Oct. 29. 1936 9Sheets-Sheet 3 IINVENTOR. J'Zrrzas M 27 4275.

A TTORNEYS.

July 4, 1939. J. M. EVANS CROSSING PROTECTIVE SYSTEM Filed Oct. 29, 19369 Sheets-Sheet 4 INVENTOR. Jkzyes M 1 7/42 5;

I HM July 4, 1939. J. M. EVANS CROSSING PROTECTIVE SYSTEM Filed Oct-29,1 936 9 Sheets-Sheet 6 ALE A TTORNEY5.

y 1939- J. M. EVANS 2,164,610-

CROSSING PROTECTIVE SYSTEM Filed 001;. 29, 1936 9 Sheets-Sheet 7INVENTOR. lma M zmws.

.4 TTORNE K5,

y 1939- I J. M. EVANS 2,164,610

GROSS ING PROTECTIVE SYSTEH INVENTOR.

July 4, 1939. J. M. EVANS CROSSING PROTECTIVE SYSTEM 9 Sheetsfihet 9Filed Oct. 29, 1936 INVENTOR. J dvyes A7. 271 4775.

ATTORNEY5.

l atented July 4, 1939 UNITED STATES PATENT QFFICE CROSSING PROTECTIVESYSTEM Application October 29, 1936, Serial No. 108,149

18 Claims.

The present invention relates to crossing protective devices of thebarrier type, that is, of the type in which a retractable andprojectable barrier is supported in a pit in a roadway or other area tobe protected, and may be automatically or otherwise projected to ablocking position and retracted therefrom under predetermined operatingconditions.

Gbjects of the present invention are to provide an improved barrierprotective system of the above identified type, so constructed andarranged as to insure proper operation under all conditions, and whichmay be relatively economically manufactured, assembled, and installed.More specific objects of the present invention are to provide aprotective system of the above stated character, embodying a pluralityof barrier devices, the projecting movements of which are effect-ed byspring mechanism associated therewith, and the retracting movements ofwhich are provided by positive driving mechanism associated therewith;to provide such a system in which the retracting mechanism embodiescrankshaft elements suitably connected to the barrier devices, andeffective to control the rate of the projecting movement; and to providesuch a system in which the connections between the spring or weightoperated projecting elements and the barriers, and the connectionsbetween the retracting elements and the barriers are resilient.

Further objects are to provide such a system in which the individualbarriers are pivotally connected to the associated casings, the pivotalconnections being such as to iioatingly restrain the barriers againstvertical, longitudinal, and transverse movements within the casing; toprovide such a system in which the barriers and casings are providedwith cooperating abutments, in conjunction with the floating barriersupports, which act to directly transmit impact forces from each barrierto the casing; to provide such a system in which the floating barriersupports comprise spring elements so disposed relative to 45 thebarriers and casings as to resiliently oppose vertical, transverse, andlongitudinal movements of the barriers; to provide such a system inwhich the just identified spring elements are positioned adjacent thepivotal connections between the barriers and the casings; and to providesuch a system embodying in addition to the just identiiied springelements, buffer elements supported within the casings, to cooperatewith the forward edges of the barriers to resiliently absorb impactforces applied to the barriers.

Further objects of the present invention are to provide a barrier systemas above described, including improved means to enable the retractingmechanism to apply a positive lifting force to the barriers undercertain circumstances; to provide such a system in which the just statedforce is applied through one or more cams associated with the barriercrankshafts and disposed to engage the barriers and positively force thesame upwardly; to provide such a system in which the cams are normallyspaced from the cooperating parts of the barrier to permit limitedfloating movements of the latter independently of the cams; to providesuch a system in which the cams are automatically retired after alifting movement thereof is completed; and to provide such a system inwhich the cam retiring movements, and restoring movements thereof, arecontrolled in accordance with the movements of the barriers.

Further objects are to provide such a system embodying improved meansfor locking the bar riers in projected position; to provide such lockingmeans embodying one or more pivotally mounted arms, responsive to thebarrier position, and swingable into and out of locking engagement withthe barriers; to provide such a system embodying improved means forselectively limiting the upward movement of the barriers topredeterminat-ely adjustable height; and to provide such a limitingmeans embodying stop members carried by the casings and disposed tocooperate with the lifting mechanism to limit the upward barrier motion.

Further objects of the present invention are to provide a barrier systemof the above stated type in which the connections between the barriersand the retracting mechanism is of a lost motion type, permitting thebarriers to be forcibly depressed against the forces of the liftingsprings or weights, independently of the positions of the retractingelements; to provide such a system embodying snubber mechanism to limitthe speed of a return movement of a barrier, after a depressingmovement, to a predetermined value; and to provide such a system inwhich the snubber mechanism is connected directly between the barriersand the casings, and while effective to limit upward barrier movement,is ineffective to limit depressing movements of the barriers.

Further objects of the present invention are to provide a barrier systemof the above stated type embodying an improved driving unit, embodyingmeans to retain the barriers in any one which appear in the followingdescription and in the appended claims, preferred but il 1ustrativeembodiments of the present invention areshown in the accompanyingdrawings, throughout the several views of which, corresponding referencecharacters are used to designate cor responding parts, and in which:

Figures 1 and 2, taken together with Figure 2' considered as positionedto the right of Figure 1:; comprise a view in perspective, with certainof the parts broken away, of the crossing barrier of the presentinvention;

Figure 3 is a fragmentary view in front elevation of the improvedbarrier, showing the structural supporting elements associatedtherewith; Figure 3A is a schematic view, illustrating the dispositionof barriers at a railroad crossing;

Figure 4 is a view in vertical section, taken along the line 4-4 ofFigure 1, showing details of the hinging and buffer construction; Figure5 is a fragmentary view in vertical section, illustrating furtherdetails of a buffer shown in Figure l;

Figure 6 is a view in vertical section, taken along the line 66 ofFigure 4, showing furthe hinging details; 7 1 Figure 7 is a fragmentaryView, partly in section, taken along the line l-'l of Figure 6;

Figure 8 is a fragmentary view in vertical section, taken along the line88 of Figure 4;

Figure 9 is a view in vertical section, taken along the line 9-9 ofFigure 1, showing detail of a crank connecting arm; V

Figure 10 is a view in vertical section, taken along the line |ill ofFigure 1, showing details of a so-called ice-breaking cam;

Figure 11 is a view, partly in vertical section, taken along the line ill l of Figure 9;

Figure 12 is a View invertical section,v taken along the line 12-!2 ofFigure 11, showing de tails of the locking arm;

Figure 13 is a view in vertical section, taken along the line l3l3 ofFigure 1, showing details of the torsion lifting springs; V

Figure 14 is a view in vertical section, taken along the line MI4 ofFigure 13;

Figure 15 is a View principally in vertical section, taken along theline |l5 of Figure l3;

Figure 16 is a fragmentary view in section, taken along the line l6i6 ofFigure 13; I

Figure 1'? is a fragmentary view in section, taken along the line ll-llof Figure 13; I

Figure 18 is a fragmentary View in vertical section taken along the linel8-l8 of Figure 15;

Figure 19 is a view in vertical section, taken along the line ill-19 ofFigure 1, showing details of one form of the snubber structure;

Figure 20 is a view in vertical section, taken along the line 2B2ll ofFigure l9.

Figure 21 is a fragmentary view in vertical section of a modifiedice-breaker construction; nd .1,

Figure 22 is a view taken along the line 22-22 of Fig. 21.

GENERAL DESCRIPTION Figures 1, 2, 3 and 3A Referring first to Figures 1,2, 3 and 3A, each barrier device comprises generally a barrier 50 whichis projectably and retractably supported in a casing 52, supported uponbeams 54 extending transversely thereof, and which are suitably imbeddedin a pit formed in the roadway with which the device is associated.Preferably, as

, shown in the diagrammatic View, Figure 3A, each crossing installationincludes at least four of the i devicestwo thereof being mounted at eachside of the protected intersection. Each of the illustrated trafilclanes A' and B (Figure 3A) is thus provided with two of the devices, onethereof being at the entering side of the intersection and theiother.thereofv being at the departing side of the intersection. In certaininstances, it is found practicable to protect only the entering side.Generally, however, it i s found advisable to protect each lane, atboththeentering and departing sidesiin orderto prevent an oncoming vehiclefrom avoiding the barrier by swerving out of the regular lane of travel.All barriers at each side of an intersection are connected together forcommon control by a single drive unit 55 individual to such side.

In Figure .3A also, it is assumed that each deviceis sufilcientlywide toprotect its entire associated lane. 'Ifo accommodate the devices tolanes of greater width, it will be appreciated that the lengths of theindividual devices may be increased. ,Alternative1y,,the devices may bemade ina variety of different lengths and two or more thereof connectedin end to end relation to ac- .commodate roadways of too great a widthto be handled conveniently by a single'device per lane. Afeature of ithe present construction is the ready adaptabilitylof the'barriers forsuch end to end du plication andthe adaptability thereof forconnectiodat, either end to' the driving unit.

As anaidYifi'appreciating the following detailed descriptive mattentheoperation as a whole of the devicemaylbe briefly summarizeda's follows:f Ihe approach of a trainer othervehicle to the crossing ,w ith l wh ichthe devices are associated, and they approach of whichis designed toactuate the ,devicefcgompletes ,the circuit for the driving motor itassociated-withthe drive. unit at each side of the intersection. Eachmotor, accordingly, releases a brake associated therewith and starts,thereby rotating the crankshaft 59 connected thereto, which i carnkshaftis connected to the barriers 50 thrc ug l' a, plurality of connectingarms 6 l. ,This action permits a plurality of torsion springs ,63,ass0ciated with each barrier, to forcethe latte-r1 upwardly, duringwhich movement it rotates (about, the pivotal connection between t herear corner thereof and the casing. After .a shortinitial raisingmovement, sufficient to bring the warningindicia' on the face of thebarri er into view, a. controller 65 individual to each driveunitinterrupt's the motor circuit and applies thebrake thereof, bringingthe barriers to rest in an inijtial er warning position. After asuitable predetermined interval, determined by timing mechanis r nhereinafter described, each controller 65 again places the, associatedmotor 51 in operation, continuing the upward movements of thebarriers.At the upper limit position,, cah .rnoto-rfifl is automatically stoppedby the associated controller 65. Upon reaching the lirnit positions,also, the barriers associated with on-coming lanesareautomaticallylocked in the raised position, The barriers associated with outgoinglanes are preferably not locked, so that they may be depressed to permitmovement of vehicles thereover. Preferably, also, the outgoing barriersare lifted to only an intermediate height, limit stops being providedfor this purpose.

As the actuating vehicle leaves the intersection, motor is again startedin the original direction and, through the arms 6|, pulls each connectedbarrier downwardly in a single, continuous movement, to its originalposition, against the force of the torsion springs 63. Upon reach ingthe original position, each motor 51 is again brought to rest by theaction of the associated controller 65.

Each barrier may thus be broadly characterized as one which is raisedthrough the influence of the torsion springs associated therewith andwhich is lowered through the force directly applied thereto through thedriving unit. The connection between the driving unit and each barrieris a lost motion one, so that the barrier may be depressed against theforce of the torsion spring during the raising rotation of the driveunit, at any time between the initial movement thereof and the time thatthe limit position locking mechanism is rendered effective. Snubbers 69are provided to prevent a too rapid or a too high rise of each barrierfollowing such a depression.

The initial lifting movement of each barrier actuates a limit switch 6'!individual to each device, which controls the circuit for usual crossingtraffic warning lights. The barrier control systems are also so arrangedthat the barrier movement is accompanied by the actuation of a pluralityof lamp units 66 located in the casing, and which, in conjunction withsuitable reflectors, act to illuminate the warning indicia located onthe face of each device. These lights remain lighted in continuouslyflashing relation from the time of initial actuation thereof until thebarrier reaches a corresponding point in its downward or returnmovement.

The drive units per se and the control systems therefor form the subjectmatter of applicants co-pending application, Serial No. 109,941, filedNovember 9, 1936, and the warning light structure for the barriers andthe control system therefor form the subject matter of applicantsco-pending application, Serial No. 108,150, filed October 29, 1936, bothof which are assigned to the assignee of the present application. Inaddition certain features of the present construction are disclosed andclaimed in the application of William G. Miller, Serial No. 125,081,filed February 10, 1937, and of Sulo M. Nampa, Serial No. 113,410, filedNovember 30, 1936, both of which are assigned to the assignee of thepresent application.

Biumnnz AND Gssnvc CONSTRUCTION Figures 1, 2, 3 and a Each barrier 50 ispreferably formed as a single, elongated, shell-like casting, generallytriangular in shape in vertical transverse section, the back of which isenclosed to form a part of the roadway when the barrier is in depressedposition, and the generally arcuate front of which is enclosed to forman impact portion and a protective skirt portion. The ends are alsopreferably enclosed to constitute protective skirts. The under side ispreferably open to accommodate the operating elements associated withthe barrier. Each enclosing end skirt 56 of each barrier 50 lies closelyadjacent the associated end 58 of the casing 52,

and so acts to prevent dirt and other foreign matter from falling intothe casing when the barrier is in the raised position. The forward skirtportion 60 lies closely adjacent the forward, upper edge lip 62 of thecasing when the barrier is in raised position and performs acorresponding function. The rectangular dimensions of each barrier 50and casing 52 are such that in the retracted position, only very smallspaces are left around the barrier edges, thus minimizing the entranceof dirt and other foreign matter into the casing.

As described in more detail in the above application, Serial No.109,941, the forward face of each barrier is provided with suitablewarning indicia, such as the letters RR and the word Stop preferablyoutlined in reflecting buttons. Cut-outs are also provided to receivelarge lenses 64. The lenses are preferably supplied from light sourcesindividual thereto and illustrated as comprising a pair of lamps 66disposed at either end of the casing adjacent the base thereof. Lightfrom the lamp units 66 is reflected through lenses 64 from a pair ofmoving reflectors which are moved in accordance with the movements ofthe barrier. Thus, a substantially uniform angle of incidence ismaintained between the roadway and the light transmitted through thelenses. Preferably, the arrangement is such that the light transmittedfrom the barrier is confined within a relatively narrow band.Accordingly, as the barrier moves upward as hereinafter described, adriver of an on-coming vehicle is confronted with a substantiallycontinuous band of red or other colored light, extending entirely acrossthe roadway and providing a highly effective warning.

The impact portion 68 of each barrier is preferably reversely formed, topresent an arcuate engaging surface. The arcuate curvature is preferably such that a substantial area is engaged by a tire of a. vehiclewhich engages the barrier. The inclination of the engaging portion 68 inits relation to the height of the barrier, is determined in accordancewith the disclosure of the copending application of Edward S. Evans,Serial No. 33,037, filed July 25, 1935, and assigned to the assignee ofthe present application. As disclosed and claimed in this co -pendingapplication, by properly relating the height and inclination of theengaging face of the barrier, a construction results which, when engagedby a vehicle, forces the front end of the vehicle upwardly with a forcesufficient to substantially counteract the forward thrust which wouldotherwise be given an occupant of the vehicle. Vehicles may thus bestopped by the barriers without injury to occupants of the vehicles.

Each casing 52, one of which, as previously stated, is individual toeach barrier 50, is preferably formed of an elongated rectangularbox-like casting, open at the top and at the bottom and disposed to besupported in the roadway pit upon the previously identified,transversely extending, I-beams 54. A plurality of transverse, inverted,channel shaped ribs I0 extend between the forward and rear walls 12 and14 of each casing, and, in cooperation with the hereinafter more fullydescribed buffers 16 carried thereby, act to support the lower edge ofthe arcuate front face of the associated barrier when, the latter is inthe retracted position. The lips 62 and 18, associated with the forwardand rear upper edges of each casing 52, cooperate with the supportingmasonry 80 in maintaining the upper surface of each casing 52 in a flushrelation to the roadway.

Each device, including a barrier 50 and a supporting casing 52, ispreferaly shipped to the point of installation in a completely assembledcondition. A preferred method of erecting the thus previously assembleddevice consists in providing the pits in the roadway with a masonryfooting 82, which forms a substantial and firm support for the I-beams54, which carry the casing 52. After thus being preliminarilypositioned, the masonry 80 may be poured around each casing 52 at thefront and rear sides thereof. In certain instances, it is desirable toform the pit deep enough to provide a chamber 8I beneath the barrier, toafford access for inspection or repair. In certain other instances, asdescribed hereinafter in more detail, it is desirable to arrange thebarriers for access from above.

SUPPORTING RELATION BETWEEN Bimnmn AND CASING Figures 1, 2, 4, 5, 6, 7,and 8 It will be appreciated that, in operation, crossing barriers ofthe type in question are subjected to an extremely heavy duty. They arerequired to successfully withstand the impact forces of vehicles ofwidely varying weights and traveling at widely varying speeds, and arerequired to bring said vehicles to rest without permitting the passagethereof into the protected intersection. Each barrier and casing isaccordingly subjected to tremendous impact forces.

The forces involved in the successful operation of a protective deviceof the kind in question have shown it to be inadvisable to utilize ausual hinging relation between each barrier and its supporting casing.The present invention provides a hinging relation between each barrierand its supporting case which is such that all impact forces applied toa barrier are transmitted directly from the barrier to the supportingwalls or ribs of the casing, and are not transmitted through theelements which form the pivotal connection between the casing and thebarrier.

Referring particularly to Figures 4, 6, '7 and 8, the rear edge of eachbarrier 50 is provided along its length with a plurality of spacedbearing bosses 90, provided with suitable bushings 92, and through whichpins 94 are passed. Each pin 94, which may and preferably is providedwith a suitable lubricant fitting 96, is journaled in spaced bosses 90formed at the upper ends of the legs of a spring arm I00. Each springarm I is pivotally connected at its lower end to a boss I02 formed in anassociated one of the previously mentioned transverse ribs 10, by meansof a pin I04, which passes through the boss I02, and the opposite endsof which are freely received in somewhat elongated slots I05 formed inthe lower ends of the legs of the spring arm I00. A compression coilspring I 08 is seated between each boss I02 and a pin IIO, which dependsfrom a cross-web II2 formed in each arm I00. Each spring I08 thus actsto urge its associated arm upwardly so that the lower ends of the armslots I06 bear against the under side of the associated pin 04. Theslots 506, however, permit each arm I00 to be depressed somewhat againstthe force of the compression springs I08. The arms I00 thus act tofioatingly vertically support the rear edge of the barrier 50.

A pair of compression springs II3, associated with each arm I00, actbetween the back II4 thereof, and the rear casing wall. and serve tocontinually urge the associated arm I 00 in a counter-clockwisedirection, as viewed in Figure 4.

One end of each spring I I3 bears directly against the base of anassociated recess II6 formed in the rear casing wall, and the other endthereof is received in a cup-like member II8, which may be suitablysecured to the back II4 of the associated arm I00.

Springs II3 are opposed by a single compression spring I20, one end ofwhich bears against the inner face of the back II4 of the associated armI00, and the outer end of which is fitted over a retaining member I22,which is supported adjacent the web I24 of the U-shaped bracket I26,which is either integrally formed with casing 52 or is suitably securedthereto, with the web I24 thereof spaced inwardly from the rear wall ofthe casing, and the legs I28 thereof spaced apart sumciently to receivethe associated arm I 00. The position, and hence the initial compressionof spring I is adjustable by means of an adjusting screw I30, which maybe locked in position by a set screw I32. Adjusting screw I30 ispreferably adjusted so that in a free condition the barrier 50 is heldby springs I20 and the opposing springs H3 in a position such that therear edge thereof is slightly inwardly spaced from the rear wall of thecasing, and the forward face thereof is spaced slightly inwardly fromthe forward wall of the casing.

Two additional springs I34 and I36, which act in opposing relation toeach other, are provided to resiliently balance or secure the barrier 50in a predetermined longitudinal position. Bolts I and I37, threaded intothe sides of arm I00, pass freely through the legs I28, and are providedwith retainers I33 and I3I which seat the outer ends of springs I34 andI30. The other ends of springs I34 and I35 are seated in recessesprovided in the legs I 28 of the previously mentioned U-shaped bracketmember I26.

With the above described arrangement, it will be evident that eachbarrier 50, supported at a plurality of points along its length, floatsvertically of the casing under the restraining influence of the springsI08, floats transversely of the associated casing under the restraininginfluence of the opposed springs H3 and I20; and floats longitudinallyof the casing under the restraining influence of the opposed springs I34and I36.

In order that forces striking the barrier of sufficient magnitude toovercome the restraining forces of the previously described balancingsprings and thus of sufficient magnitude to displace the barrier in thecasing, may be transmitted directly between the barrier and the casing,independently of the hinge pins 94 and I04, abutment means are providedto absorb the vertical, transverse and longitudinal components of suchforces.

To absorb vertically directed forces, a foot I is formed within thebarrier adjacent each boss 90 and which, in the free position of thebarrier, occupies a position in slightly spaced relation to the uppersurface I42 of the associated U-shaped brackets I20. The spacing betweenfoot I40 and the surface I42 is less than the lost motion in theconnection between each arm I00 and the associated pins I04.Accordingly, any vertical force of sulficient magnitude to substantiallycompress the springs I08, causes the feet M0 to engage the supportingsurfaces I42, so that all of the vertical load transmitted between therear edge of the barrier and the casing is thus transmitted directlybetween the feet I40 and the supporting surfaces I42. Vertical forcesdirected against the front edge of the barrier are absorbed by thehereinafter described buffers 16.

Similarly, to absorb any force sufficient to cause the barrier feet tomove rearwardly in the casing, or to the right, as viewed in Figure 4,the previously mentioned rear edge rib formation I8 of the casing 52 ismade sufliciently heavy to form wardly directed forces, that is, forcestending to cause the barrier to move forwardly within the housing or tothe left, as viewed in Figure 4, a

plurality of arcuately formed ribs I44 are provided in spaced relationalong the forward wall of the casing, and which extend toward the rearwall. In the free position of the barrier, the arcuate forward face 60thereof lies in slightly spaced relation to the ribs I44. A forwardmovement of the barrier, against the resistance of the springs I20,howevenbrings the forward barrier face 60 directly into engagement withthe ribs I 44, which constitute a positive limit to such for- J Wardmotion, and relieves the springs I20 of further load. I

Forces acting longitudinally of the barrier, if

sufficient to compress one or the: other of the rier directly intoabutting relation to the ends 58 springs I34 and I36, bring the ends 56of the bar- I the assembly comprising the spring and the two of thecasing, which members'thus act to directly transmit such longitudinalforces from the bar rier to the casing. Each of the buffer plates I6,one of which is associated with each of the previously mentionedtransverse ribs I0, comprises generally a flat upper plate-like portionwhich forms a seat, and a cylindrical boss portion I50 formed integrallyfront edge of the barrier, however, and forcing the latter downwardly,initially compresses the springs I60. If the force is of suflicientmagnitude, it compresses the springs I60 suiiiciently to bring the undersides of the plate portions of the buffers I6 into engagement with thebases of the recesses I56 provided therefor in the transverse ribs,which recesses thus form a positive limit to such downward movement andact to transmit such vertical force directly from the barrier to thecasing through the ribs I0.

A structural feature of importance in connection with the buffer platesand associated spring mechanism is shown in Figure 5. In Figure 5, whichshows the upper and lower spring retainers I51 and I62 in section, thelower spring retainer I62 is provided with a drilled opening I10, largeenough to freely pass an adjusting stud I12, the threaded end of whichis threadably received in an internally threaded opening I14 provided inthe upper spring retainer I57. The base II6 of the transverse rib I isprovided with 'an opening II8 sufliciently large to freely pass the headof the adjusting stud IIZ. In assembling the parts, the buffer plate I6is first freely dropped into the recess I56 provided therefor in thetransverse rib. Thereafter, the pin I54 is inserted in place. As apreliminary to inserting the spring I60, the adjusting stud is turnedinto the opening II4 sufficiently far to compress the spring I60 andbring the two spring retainers I51 and I62 sufliciently close to eachother that retainers may be freely slipped between the base of thebuffer plate and the upper surface of the 7 portion H6. The finalassembly step may conand force the lower retainers against the portionI16 and force the upper retainers in the seat I58.

with the seat portion and extending downwardly therefrom. An elongatedopening I52 extends through the boss portion and forms a lost motionconnection with a retaining pin I54 which passes therethrough, and theopposite ends of which are supported in openings (not shown) in theoppo-v site sides of the channel shaped transverse rib I0. Each pin I54,therefore, acts to loosely prevent displacement of the associated bufferplate I6 from their supporting ribs. The supporting ribs are eachprovided with recesses or depressions I56 within which the plateportions of the buffers are somewhat loosely received.

The under side of each boss portion I50 rests upon an upper springretainer II, preferably of circular construction, and the upper surfaceof the marginal edge of which bears against a seat I58 provided thereforin the associated rib I0. A compression spring I60 is seated betweeneach of the upper retaining member I51 and a similarly constructed lowerspring retaining member I62, which is supported upon a seat I64 providedtherefor in the base of the associated transverse rib I0.

The barrier 50 is provided with an inturned flange I66, which extendsthroughout the length thereof, and is reinforced at a plurality ofspaced points by ribs I66 and by additional ribs I69. In the retractedposition of the barrier, th flange I66 rests upon and is supported bythe plurality of buffer plates I6, which floatingly retain the barrierin the position of the parts illustrated in Figure 4 under the influenceof the supporting springs I60. 7 Any vertical force acting on theFigures 1, 2, 9, 10, 11 and 12 As previously stated, in a general way,each barrier 50 is provided with a crankshaft 59 which extendslongitudinally therethrough, and has a lost motion connection with eachof a plurality of arms 6I, which are respectively pivotally connected tothe upper surface of the barrier. The crankshafts are actuated by thedrive units 55 and one complete revolution of each thereof is effectiveto permit one complete raising movement under the influence of thepreviously mentioned torsion springs 63 and a complete retractingmovement, approximately 180 degrees of travel being involved in each ofthe projecting and retracting movements. The lost motion connectionbetween each crankshaft and its associated connecting arm permits thebarrier to be retracted against the force of the torsion springs,independently of the crankshaft movement. It also permits the barriermovement to be interrupted at any point in its travel, independently ofthe crankshaft movement, so that the upper limit of travel of a barriermay be determined independently of the throw of the associatedcrankshaft. During travel of the crankshaft in the lowering 180 degreesof movement, however, the offsets positively engage the connecting armsand correspondingly positively effect a barrier retracting movement.

' As shown generally in Figures 1 and 2, and in greater detail inFigures 9 and 11, the crankshaft 59 associated with each barrier 56 isrotatably journaled within the associated casing in bearings formed bypillow blocks I8, which are supported upon the transverse ribs I andwhich may be secured thereto in any suitable manner. As best shown inFigure 11, each shaft 59 is formed in sections 5911 and 59b, connectedtogether by members I82 which constitute offsets, and which are keyed bykeys I6I to the shaft sections. The number of offsets depends of courseupon the number of arms 6| desired. In the illustrated arrangement, twoconnecting arms 6| are provided. The lefthand end of crankshaft 59, asviewed in Figure 1, extends slightly outwardly to the end of the casing52, which end is provided with a suitable opening to accommodate thecrankshaft, and is coupled to the shaft of the drive unit by aconventional flexible coupling I86. The other end of the crankshaft maybe adapted for corresponding connection to the 2 crankshaft of animmediately adjacent barrier.

Referring particularly to Figures 9 and 11,

' each arm 6| comprises a generally U-shaped member, the free ends ofthe legs I88 and I96 of which are connected together by a stud I92, and

are maintained in substantially parallel spaced relation by a combinedspacing and bearing block fI94, the curvatiue of the inner face of which3 [shaft 59. The two legs I66 and I96 thus define corresponds to thecurvature of the shaft portion I'96associated with the offset I82 in thecrank- "a slot within which the shaft portion I96 may freelymoverelative to the arms 6| in a direc- 2 tion' longitudinally of thelatter.

The base of each U-shaped arm BI is somewhat.

wider than the width of the slot provided for the shaft section I96, andthis enlarged portion receives a compression spring I 99, one end ofwhich isseated against the base of the U-shaped mem- M iii.

ber and the other end of which bears against a retaining plate 200 Plate296 is threadably secured to the free end of a stud 22, which freelypasses through an opening provided therefor in the base of the U-shapedmember, and is provided with a head 294. Each head 204 is pivotallyconnected by a pin 266 to a clevis 208 either formed integrally with orsuitably rigidly secured to the under side of the barrier 50.

The parts are shown in Figures 9 and 11 in the projected position, inwhich the offsets I82 of the crankshafts are in their extreme positionsof upward barrier movement. As will be evident, rotation of crankshaft59 in either a clockwise or I a counter-clockwise direction from theposition shown in Figure 9, is effective to lower the barrier 50 throughthe connections between arm BI and the crankshaft 59, the lowering forcebeing transmitted through the compression springs I98. A resilientconnection is thus provided between the crankshaft and the barrier.

i to through the torsion springs as hereinafter described. Through thelost motion connection between the crankshaft portion I96 and each farm6|, the crankshaft 53 is effective to limit the 50 is of progressivelyincreasing radius. fully retracted position of the barrier, each foot 2Mlies in spaced relation to portion a. After a rate of rise of thebarrier 50, but is ineffective to cause a rising movement.

As will be further appreciated, the provision of a structure in which acomplete raising and lowering cycle involves 860 degrees of crankshaftmovement, avoids the necessity of providing reversing mechanism for thedriving motor associated with the driving unit, and correspondinglysimplifies the control and arrangement thereof.

In instances where the device remains in the retracted position for longperiods of time, and under severe weather conditions, it may be expectedthat more or less ice will accumulate between the barrier and the casingtherefor which may oppose the projecting movement of the barrier with aforce in excess of the force applied thereto through the torsion springs63. In the present construction, the arrangement is such that toinitially break loose the barrier, the lifting force applied to thebarrier through the torsion spring 63 is supplemented by the drivingforce of the drive unit. Referring particularly to Figures 1, 2, and 10,a pair of cams Eli) are suitably keyed by keys 2I2 to the crankshaft 59in position. for cooperative engagement with seats 2I4 formed at thebases of the stiffening ribs I69.

Each cam 2l0 is provided with a major peripheral portion a of uniformradius, such as to lie in slightly spaced relation to the associatedfoot 2I4 when the latter is lowered. The portion 2) which represents anangle of between 49 and In the cam shaft movement of a few degrees, forex ample, 15 to 20, each foot 2M is engaged by the periphery of theassociated cam at the low end of portion b. The parts are shown in Figure 10 with the foot 2M in engagement with the cam portion of maximumradius, which represents the position attained by the parts after Ibetween 55 and 70 of crankshaft travel.

In normal operation, in which the forces of the torsion springs 63 aresufiicient to lift the barrier, ,the barrier lifting movements carry theseats 2H3 away from the associated cams. In instances, however, wherethe torsion spring forces are insufficient to lift the barrier, theseats 2M may remain in engagement with the associated cams during all orpart of the 40 to 50 of crankshaft travel, represented by the angulardisplacement between the limits of cam portion b. In such instances, thecams, due to their progressively increasing radius, apply a positiveupward force to the feet 2 I4 which, of course, supplement the forces ofthe torsion springs and positively breaks loose the barrier. It will beappreciated that, when the thus combined forces finally overcome theresistance to motion of the barrier, the barrier will then rise to thenormal position corresponding to the then angular position of thecrankshaft. It will be appreciated, also, that the total change inradius of the cam 25!], as well as the angular displacement between thepoints of minimum and maximum radius of the portion 1) thereof ofincreasing radius, depends upon operating conditions and may, in certaininstances, be less than the described displacement, and in otherinstances, may be more than the described displacement.

As stated in the foregoing general description of operation of thedevice, the barriers associated with the on-coming lanes of travel arearranged to be positively locked in the fully raised positions bylocking mechanism which, while ineffective during the initial raisingmovements of the barrier, is rendered effective as the barrier reachesits maximum height, It is preferred, however, that the barriersassociated with the outgoing traffic lanes be arranged so that they maybe depressed at any time, so that vehicles trapped between the incomingand outgoing barriers may pass over the outgoing barriers withoutsubstantial obstruction. In accordance with the present application, thelocking mechanism for the on-coming barriers is directly controlled bythe cam shaft associated with each barrier.

Referring particularly to Figs. 1, 2, 11 and 12, a pair of arms 226 and222 are pivotally supported within each casing by pins 224 and 226,which in turn are journaled in. clevises and 236, which may be formedintegrally with or rigidly secured to the flanges of the transverse ribs10. Both the arms 226 and 222 and the elements directly associatedtherewith are the same and a description of one will serve for both.

Referring particularly to Figures 11 12, the arm 226 is of bell crankformation, one arm thereof being provided with a roller 232, disposed tocontinuously engage the periphery of a earn 234 which is keyed by a key236 to the cam shaft 59. The cam 234 is of uniform radius throughoutsubstantially its periphery, but is provided with a portion 238 ofreduced radius which registers with the rollers 232 at the angularposition of the cam shaft 59 corresponding to the fully projectedposition of the barrier.

The bell crank portion of arm 226, which carries the roller 232, is alsoprovided with a seat 246, against which one end of a compression spring242 bears. The other end of the compression spring 242 is secured over aboss 244 formed on a rearwardly extending projection of the clevis 228.Spring 242 thus continuously urges bell crank 220 in a counter-clockwisedirection, as viewed in Figure 12. Except when the barrier is in thefully projected position, the portion of maximum radius of cam 234engages roller 232 and thus retains the end 246 of bell crank 22!] in aposition to the right of that shown in Figure 12, in which it isinwardly spaced from the face 60 of the barrier 56. As the barrierreaches its fully projected position, however, the seat 248 provided forco-operation with the end 246 of the bell crank passes above such end.At this time also the cam portion 238 of reduced radius registers withthe roller 232, permitting the bell crank 226 to be swung in acounter-clockwise direction under the influence of spring 242, to thelocking position shown in Figure 12, in which position, it lies directlybelow the barrier portion 248, and forms a positive block againstdownward barrier movement.

As soon as a barrier retracting movement is begun by the crankshaft 59,roller 232 is engaged by the cam portion of maximum radius. and isthereby forcibly moved to swing the bell crank 22!] out of lockingengagement with the face of the barrier. The very short interval of camshaft movement which is thus necessary before the barrier is released bythe bell cranks 226 and 222, is readily absorbed by the previouslydescribed springs I96 associated with the retracting arms 6|.

As described generally above, it is desirable to permit the barriersassociated with outgoing lanes of travel to be depressed at any time. Accordingly, it is preferred to omit the just described locking mechanismfrom the outgoing barriers. Moreover, as described hereinafter, it ispreferred to provide mechanism to limit the travel of the outgoingbarriers to an intermediate height. This limiting mechanism ispreferably directly associated with the torsion spring and is describedin connection therewith.

TORSION SPRING LIFTING MEOHANIsM AND TRAVEL LIMITING MECHANISM Figures1, 2, 13, 14, 15, 16, 17 and 18 Referring particularly to Figures 1, 2and 13 through 18, two of the torsion springs 63 are shown as connectedbetween the barrier 56 and the casing 52 for forcibly projecting thebarrier to the raised position. The construction and arrangement of bothof the springs 63 is the same, so that the description of one will servefor both. It will be understood also that, in a broad sense, a greaternumber or a lesser number of the springs may be utilized.

Considering particularly the lefthand spring 63 of Fig. 15, therighthand end thereof is rotatably supported upon a hub 260 shown asformed integrally with the reduced rearward portion 262 of one of theribs (Figure 1). The lefthand end of the just mentioned spring 63 isrotatably supported on a hub 264 which forms part of a generallytriangularly shaped lifting bracket designated as a whole as 266. Thehub 264 is rotatably journaled upon a trunnion 268 which is shown asformed integrally with a bracket 210 which is rigidly secured as by thestuds 212 to the rear wall 14 of the casing 52. Certain of the studs 212also support a spring protective apron 213.

The end 216 of spring 63 is connected to the rear wall '74 of casing 52by a link 218 of adjustable length. One end of the link 218 is providedwith the loop 280 which passes over the free end of the spring, and theother end of the link 218 is threaded for cooperation with an adjustingnut 282. The adjusting nut 282 is provided with a tubular shank portion284, of sufficient length to extend all of the way through the opening266 formed in the base of the casing, and so protects the threads of thestud 218. The head of the nut 282, it will be appreciated, issufficiently large to have a bearing engagement with the rim of theopening 285.

The back 296 of the triangular lifting bracket 266 is of channelformation, and the upper lefthand corner thereof, as viewed in Figure13, forms a clevis 292, in which a pin 294 is journaled, which pin formsa pivotal connection between the associated lifting arm 296 and thelifting bracket 266. The channel formation of the back 296 also forms aclevis which supports a pin 298, over which the remaining free end 300of the associated spring 63 is hooked. Preferably, and as illustrated,the just mentioned clevis portion of each lifting bracket 266 isprovided with additional cut-outs, such as 302, which may in certaininstances be provided with pins to replace the pin 298 and provide asubstantial adjustment of the'initial torsional stress to which theassociated lifting spring is subjected. This adjustment may, as will beappreciated, be refined by suitably adjusting the nut 232 associatedwith the link 218, which connects the other end of each spring to thehousing.

The lefthand flange 364 of the channel shaped back 296, as viewed inFigure 16, is extended to give the bracket its triangular shape andforms the connection between the back portion 296 and the previouslymentioned spring carrying hub 264.

Each arm 296, which forms a connection between the lifting bracket 266and the barrier, is of a link formation and comprises a boss 316 formedintegrally at one end thereof for cooperation with the previouslymentioned con necting pin 294, and a second boss 3l2, resilientlyconnected to the other end of the arm. The boss 312 is connected by apin 314 to a clevis 316 provided therefor in the barrier 59. The shank318 of each boss 312 is slidably received in an opening 329 providedtherefor in the end of the arm 296. A compression spring 322 surroundseach shank 318, and is seated between an adjustable nut 324 carried bythe latter, and the end of the arm 296. The nut 324 is provided withears 325 which protrude from either side of the arm 296 and preventturning thereof. The upper end of each arm 296 abuts the lower sur faceof the connecting boss 312, so that a positive driving connection isprovided between each lifting bracket 266 and the barrier 59.

As will be appreciated, each retracting move ment of the barrier 56under the influence of the crankshaft 59 and the associated connectingarms 51, as previously described, forces the lifting arms 296downwardly, correspondingly rotating the lifting brackets 266 in .acounterclockwise direction, as viewed in Figure 13, and winding up thetorsional springs 63 to thereby load the springs. On the other hand,rotation of crankshaft 59 throughout the lifting part of its travelrelieves the downward force on the barrier, and permits the torsionsprings 63 to unwind under the influence of the previously appliedstress, forcing the lifting brackets 266 in a clockwise direction, asviewed in Figure 13, and correspondingly forcing the arms 296 andbarrier 50 in the upward direction. The resilient connection between thelifting arms 296 and the bosses 312 associated therewith is useful inpreventing sudden jars or impacts against the barrier 56 when in araised position, from being transmitted directly to the lifting brackets256. This resilient connection, however, is of particular value where itis desired to provide means for positively limiting the rotation of thelifting brackets 266, as where it is desired to limit the liftingmovement of the barriers to a point lower than would be permitted by thetravel of the crankshaft 59 and connecting arms 61.

In accordance with the present construction, this supplemental upwardmovement limiting mechanism is applied to the barriers associated withthe outgoing lanes of travel, in order to limit the travel thereof to anintermediate height. This limiting mechanism may, however, be applied tothe barriers associated with the on-com ing lanes of travel, and soadjusted as to permit the barriers to rise to the full height.

Referring particularly to Figure 14, a relatively heavy U-shaped member336 is associated with each torsional spring 63. The flanges of eachmember 330 are connected to associated ones of the transverse ribs '10by studs 332. Preferably also at least one of the flanges associatedwith each U-shaped bracket is turned over, as indicated at 334, toco-operate with the base of the associated transverse rib '10 andsupplement the securing effect of the studs 332. The web of eachU-shaped member 339 is disposed for engagement by the portion 394 of theassociated lifting bracket 266 when the latter has rotated to thedesired degree, and so forms a positive limit to further movementthereof. It will be evident that the stop members 338 may be adjusted tolimit the travel of the associated barrier to any desired degree.Preferably, in association with the outgoing barriers, the member 333limits the rise thereof to approximately two-thirds the rise of thebarriers associated with the on-coming lanes of travel.

After a barriers rising movement has been stopped by the stop member anyimpact or external force applied thereto, tending to cause a furtherupward movement thereof, is absorbed by the resilient connectionsbetween the lifting arms 296 and the associated bosses 3E2 provided bysprings 322.

As will be appreciated, the pins 266 associated with arms 6i, and thepins 324 associated with arms 296, are readily removable, to therebydisconnect the barrier 59 from the crankshaft 59 and from the torsionspring mechanism, and permit it to be freely rotated to a position toafford ready access to the interior of the structure from above. Toafford access to the pins 296 and 314 when the barriers are retracted, aplurality of hand openings 315, closable by removable plates 31'5, arepreferably provided at appropriate points in the barrier upper surface(Figure 13).

SNUBBER MECHANISM Figures 1, 19 and 20 In practice, the projectingmovements of the barriers is usually begun when the train or othervehicle, the approach of which may be relied upon to actuate thebarriers, is a substantial distance away from the crossing to beprotected. This initial movement may be expected to occur at a time whenhighway vehicles are too close to the barriers to permit a normal stopthereof. To enable such vehicles to pass over the partially raisedbarriers, the previously described provision for depressing the barriersagainst the forces of the torsional lifting springs, and independentlyof the angular positions of the barrier crankshafts, is very desirableif not essential. Similarly, it may occur from time to time that avehicle will be trapped between the barriers at either side of anintersection or crossing and in such instances, it is desirable that thebarrier construction permit such trapped vehicle to depress the barriersand pass thereover without substantial obstruction.

While it is desirable, under the conditions above mentioned, thatvehicles be able to depress the barriers rapidly and without a too greatresisting force therefrom, it is equally desirable to retard the returnmovements to the raised positions of the barriers, after beingdepressed. In the absence of a retarding mechanism, substantial injuryto the under-frame portions of the depressing vehicles may occur.

With the above considerations in mind, it is preferred to provide thebarrier of the present construction with snubber or motion checkingmechanism, so connected thereto as to permit a free and unimpededdepressing movement, but to limit the return or raising movement of thebarriers to a predetermined value. This predetermined rate of returnmovement preferably is not greatly in excess of the normal rate of riseas provided by the carrier crankshaft in the normal raising motion ofthe barriers. Preferably, the snubber is connected directly between eachbarrier and the associated casing, although, in a broad sense, otherrelationships are practical.

In the broader aspects of the present invention,

the snubber mechanism .may be constructed in various ways. Onesuitableconstruction is described and claimed in the co-pendingapplication.

of Sulo M. Nampa, Serial No. 113,410, filed November 30, 1936, andassigned to the same assignee as the present application. An alternativeconstruction is shown inFigures 19 and 20 of the present application,and embodies generally a braking member 340, a one-way or over runningclutch member 342, and. a connecting member 344, by which the snubber isconnected to the barrier 55. The just identified elements are supportedwithin the casing 52 upon a forwardly extending bracket 346, secured tothe rear casing wall by studs 348, and provided with aplurality ofbearing bosses 35B, 352, and 354, within which the shaft elements of thesnubber are journaled.

The connecting element 344 comprises a triple sprocket wh'eel which isdrivingly connected bya pin 36! to the snubber driveshaft343. A multiplesprocket chain 345 is trained over the sprocket wheel, and one endthereof, is connected to the under surface of the barrier 50 by a clevis341. The other end of the sprocket chain is similarly connected by aclevis 349 to an inwardly turned flange portion 351 provided at thebase. of, the forward face of the barrier 51!.

With this arrangement,it will be seenthat an upward movement of barrier50 causes, through the sprocket chain 345 and the sprocket344, aclockwise rotation of the snubber shaft 343,. as viewed in Figure 19,and that a downward or depressing movement of the, barrier effects acounter-clockwise rotation of shaft 343, as viewed in the same figure.

The clutch member 342 comprises a pair of opposed housing members 353and 355, which are suitably secured together to form anenclosed chamber,and which chamber is drivingly connected to the snubber brakeshaft 351by a tapered pin 356, which passes through brake shaft and also throughthe hub of the left-hand housing member 353, as viewed in Figure 20. The

mechanism within the clutch housing (not shown in detail), may comprise,for example, a plurality of dogs drivingly connected to the housingmembers, and a plurality of ratchet members drivingly connected to thedrive shaft 343, which extends into the clutch housing. The relation ofthe dogs and ratchets is such that counter-clockwise rotation of thedrive shaft 343, which corresponds to a depressing movement of thebarrier 50,-permits the dogs to .be cammed out of operative relation tothe ratchet teeth but that clockwise rotation of shaft 343, brings thedogs into driving contact with the ratchet teeth. The distribution ofthe dogs and the ratchet teeth may be such that only a limited angularrotation in the driving direction is necessary to bring the dogs intopositive driving relation with the ratchet teeth. Sub-' stantially nolost motion in the driving direction is, therefore, present in theoperation of the clutch.

The braking element 340 of the snubber comprises a stationary brakemember 358, non-rotatably secured to the supporting structure, andthrough which the brake shaft 35! passes and a movable brake member 359which is axially movable into and out of braking engagement with member358, and is drivingly connected, as previously stated, to the clutchmember 342 by the pin 35%. The movable braking member 359 is relativelyheavily formed to give it a flywheel effect, and may be drivinglyconnected to the clutch housing 353 through a detent connectioncomprising a plurality of cams formed thereon which engage in taperednotches formed in the face of the hub of member 353 (not shown). Aspring may be seated between the movable and stationary brake members tourge the cams intothe notches to render the driving connectioneffective.

With this arrangement, it will be appreciated that rotation of the driveshaft 343 in a clockwise direction, as viewed in Figure 19, whichrepresents the driving direction of the clutch 342., effects acorresponding rotation in the same direction of the hub 353; and alsoeffects rotation in a corresponding direction of the movable brakemember 358 through the detent connection. As long as the rates ofrotation of the movable brake member 353 and the hub 353 are the same,it will be appreciated that brake member 359 does not move axially. If,however, a relative rotation occurs between brake member 359 and hub353, the former is caused to advance or recede relative to thestationary brake member 358, by the riding up of the cams along thewalls of the notches.

Due to the flywheel effect of the movable brake member 359, the movablebrake member 359 lags behind the hub 353 in response to any accelerationof the latter. This lag causes the movable brake member to move intoengagement with the stationary brake member 353, thereby imposing a dragthereon and also imposing a drag on the hub 353. In instances where theshaft .35! tends to accelerate at a relatively high rate, the brakingeffect thus provided is substantial and may become so great as to bringthe brake shaft 351 to rest. As soon as hub 353 assumes a position ofrest, the torsion spring is effective to break the brake members 358 and359 loose from each other by forcing the cam into the notches ag in. andthus release the hub A rotative advance of the hub theref re. occur in aseries of starts and stops. the not rate of advance be ng l mited to asuitable de ired value. determ ned by the desi n Characteristics of thesnubber elements. The snubber. accordingly. effectively acts to preventa rise of the barrie in excess of a predeterm ned value, while at thesame time. because of the over running nature of the clu ch 342, doesnot n erf re n an y with a depressing movement of the barrier 5c.

SUMMARY or OPERATION AS A WHoLE Summarizing th operation of the systemas a Whole, all of the barriers at protective crossings normally occupythe retracted positions in which the upper barrier surfaces lie flushwith the supporting roadway and act as continuations thereof, and inwhich positions they are held by brakes associated with the drive units.In response to the approach of a train or other vehicle to the crossingto be protected, the motor 5? of the drive unit 65, one of which isprovided at each side of the crossing, starts in operation, initiating aprojecting movement of the barriers connected thereto. The projectingmovement occurs due to the force directly applied to the barriersthrough torsion springs 33 individual thereto, but at a rate determinedby the rate of angular movement of the crankshaft 59 of the barriers. Inthe event that the lifting forces applied to the barriers through thetorsion springs are ineffective to cause an upward movement thereof, asin instances where ice has collected within the barriers, the icebreaking cams 2H] carried by the crankshafts supply positive liftingforces to the barriers through the cooperating feet 2l4 provided on thebarrier ribs.

When the barriers reach an intermediate height, which may be called awarning height, the controller 65 associated with each drive unit 55,automatically brings the associated motor 51 to rest, correspondinglystopping the barriers connected thereto. The brake elements associatedwith each drive motor 51 retain the barriers in positions of restagainst the lifting forces of the torsion springs.

At the expiration of a predetermined interval, determined by the timingmechanism associated with the controller 65, each motor 51 is againautomaticaly started and permits the barrier projecting movement to becontinued to a limit position under the influence of the torsion springs63. The barriers associated with the on-coming traffic lanes arepermitted to continue to a maximum projected height, in which positionthey are automatically locked against downward movement by the lockingarms 220 and 222. The barriers associated with the outgoing lanes oftravel are preferably interrupted at a height intermediate the warningheight and the just identified maximum height, this interruption beingprovided by the stopping members 330, which engage the lifting bracket266 associated with the torsion springs 63.

The on-coming and outgoing barriers thus occupy the last mentionedprojected positions thereof as long as the vehicle which initiated theiroperation remains Within a predetermined block associated with theintersection. As soon as the actuating vehicle passes beyond such block,the motors 57 associated with the barriers at the op posite sides of theintersection are again placed in operation, rotating in the samedirection, and act through the arms 6! associated with the crank shafts59, to forcibly retract the barriers against the forces of the torsionsprings 63. When the barriers reach the original retracted positions,the motors are again stopped and the brake elements thereof automaticalyapplied, and so retain the barriers in the retracted position againstthe forces of the torsion springs 63.

As an incident to the actuation of the barriers, the warning lightsystems associated therewith are automatically placed in operation inaccordance with the disclosure of the previously identified application,Serial No. 108,150, filed October 29, 1936, and serve to provide aneffective warning of the barrier action.

The lost motion connections between each crankshaft lifting arm BI andthe associated crank 58 permit the outgoing barriers to be forciblydepressed against the forces of the torsion springs 63 at any stage inthe movement thereof, and permit the on-coming barriers to be depressedexcept at such times as the locking arms 220 and 222 are in lookingposition. The depressing movements of the barriers are unimpeded by thesnubber mechanism, but the return movements thereof are maintained at alow rate, commensurate with the normal rate of rise thereof. Vehiclestoo close to the barriers to permit a normal stop thereof at the timethe upward movement thereof is begun, as well as vehicles trappedbetween the barriers, are permitted to pass thereover withoutsubstantial obstruction.

In View of the resilient floating connections between each barrier 50and the associated casing, provided by the springs H18, H3, I20, and I34and l 36, as well as by the buffer plates 76, each barrier 50 isnormally supported in slightly spaced rela tion from the rear, front,and end walls of the associated casing. The just identified springs alsoresiliently oppose any vertical, transverse, or longitudinal impactforces to which a barrier is subjected. In the event such forces are ofsufiicient magnitude to overcome the spring resisting forces and causesubstantial movements of the barriers within the casings, the barriersare brought into engagement with abutments provided in the associatedcasings, and such forces are, therefore, transmitted through suchabutments directly between the barriers and the casings.

MODIFIED ICE-BREAKING CAM CONSTRUCTION Figures 21 and 22 Referringparticularly to Figs. 21 and 22, an ice-breaker cam construction isillustrated, which represents an improvement over the constructiondescribed particularly with reference to Figs. 10 and 11, for thereasons that, among others, the ice-breaking cams are automaticallyretired from co-0perative relation to the barrier feet after apredetermined amount of crankshaft travel, in order that the barrierfeet may not strike the raised portion of the cams when the barriers areforcibly depressed, as by the passage thereover of a vehicle.

In Figs. 21 and 22 the general construction and operation is asdescribed with reference to the preceding figures, which relation isindicated by the use of corresponding reference characters with thesubscripts b. The cams 4H], a plurality of which are used, as in thecase of cams 2H], and all of which are similarly constructed andarranged, are splined as by keys 412 to the crankshaft 59b, for movementbetween the illustrated position and a retired position to the leftthereof. Each cam 4I0 comprises a portion 4l5 extending between thecharacters 1' and y which is of progressively increasing redius. In thenormal or fully retracted position of the parts, each barrier foot 4lies in slightly spaced relation above the portion MS of the associatedcam 4Ill, permitting a limited amount of free floating action of thebarrier, as previously described. In such retracted position the barrierfeet I661) rest upon and are supported by the buffers 16b.

In addition to being provided with the cam portion MS of increasingradius, each cam M0 is also provided with a radially extending fin 4|6,disposed in axially offset relation to such cam portion. In theretracted positions of the parts, each fin 4I6 lies between theassociated foot 414 and a downwardly projecting finger 4IB securedthereto as by a stud 420.

Each cam 4l0 is also provided with a restoring cam portion 422 whichextends through a cirbumferential angle of about 120, and whichco-operates as hereinafter described with a stationary stop 424 torestore the member 4|!) to the illustrated position from a retiredposition to the left of that shown. Each stop 424 is carried upon abracket 426, suitably and rigidly secured to one flange of one of thetransverse ribs 10b. A spring 428, individual to each cam 4"], havingits opposite ends secured to the shaft 591), as by the stud 430 and tothe cam 4l0 respectively, is under tension when the parts are in thepositions shown, and thus acts to urge the associated cam 410 to aposition to the left of that shown in which retired position it is outof range of the .associated foot 414.

In the normal operation of the parts, a raising movement of the barrier50b is initiated by rotating the crank shaft 59b in thecounter-clockwise direction as viewed in Fig. 24. As previouslydescribed, this rotation of the crankshaft 59b renders the torsionlifting springs effective to project the barrier upwardly. This upwardprojecting movement of the barrier carries feet M l away from theassociated cam portions M5 at a rate which is in excess of the rate ofincrease of the cam radii between the points a: and y. It also carriesthe finger M8 away from the fin M6 at a rate in excess of the rate ofincrease of the radius of fine 416. Accordingly, a relatively smallangular movement of the crankshaft 59b normally permits the barrier 56bto rise sufficiently to bring each finger M3 out of range of theassociated fin M6. This slight angular movement of the crankshaft alsomoves each cam 422 be yond the range of the associated stop $24. Theseactions release the cams MG, and permit them to move to the left underthe influence of the springs 428. This leftward movement moves each camM out of alignment with the associated seat did. Accordingly, should thebarrier 502) be forcibly depressed at any time after the just mentionedslight angular movement of the crankshaft the cam 4 l 0 does notinterfere with the depressing movement.

On the other hand, if the barrier is forcibly retained in the retractedillustrated position, by an accumulation of ice, or the like, thetorsion lifting springs may not exert a sufiicient force to initiate thebarrier projecting movement. In this instance while the slight angularmovement of the crankshaft 59b is sufficient to bring the cams All? outof range of the stops 424, axial movement of the cams Mil to the retiredposition is prevented both by the friction between the cams 415 and theseats 4M and/or by the en-- gagement between the fins M6 and the fingersM8. Cams M0 thus remain in alignment with the associated seats 4M untilsuch a time as the cam rotation moves the fins Ht out of range of thefingers M8 or, at least until the positive upward lifting force appliedto the feet M4 by the cams M5 breaks loose the barrier. When the cams M5break loose the barrier, the barrier immediately rises to a positioncorresponding to the then angular position of the crankshaft, movingfingers M8 away from the fins M6, and permitting the cams Hi! to bepulled to the left under the influence of the spring #328. It will beseen, accordingly, that the release of each cam llfl to its retiredleft-hand position occurs immediately after the breaking loose of thebarrier, and occurs immediately after the barrier rises far enough torelease the fins ME from the fingers H8.

Considering now the downward or retracting movement of the barrier aseffected by the crankshaft 592), continued rotation of crankshaft 59b inthe counter-clockwise direction is effective, through arms iii, to pullthe barrier downwardly against the force of the lifting torsion springs.In the course of this continued counter-clockwise movement of crankshaft591), each cam Q22 is brought opposite the associated stop 24. Continuedcounter-clockwise rotation, accordingly, renders stops 52d effective toforce cams did to the right as viewed in Fig. 22, against the force ofthe springs 428. The continued counter-clockwise rotation of the crankshaft 5% also brings the end 4I6a of each fin 4H5 into range of theassociated finger 418 and foot di l. This occurs at a time when eachstop 424 has moved the mem ber 4H] sufficiently far to the right toenable each pin M6 to enter the space between a finger M8 and a foot4|4. By the time the crank shaft rotation brings the barrier to thefully retracted position, accordingly, the ice-breaking structure againassumes the position shown in Figs. 21 and 22, in which positions theparts are in readiness for a duplicate operation.

Although specific embodiments of the present invention have beendescribed, it will be evident that various modifications in the form,number and arrangement of parts-may be made within the spirit and scopeof the invention.

What I claim is:

1. In a protective system embodying a casing and a barrier hingedlysupported therein for selective projection and retraction, thecombination of a hinge arm swingably connected at one end to saidbarrier and swingably connected at the other end to said casing, andspring means acting on said arm to resiliently oppose vertical,transverse and longitudinal components of impact forces on said barrier.

2. In a protective system embodying a casing and a barrier pivotallysupported in said casing, said barrier having an impact surface disposedwhen in retracted position to lie in slightly spaced relation to aforward wall of said casing, means for resiliently opposing movement ofsaid impact surface into engagement with said forward wall, and aplurality of ribs disposed along said forward wall for engagement bysaid impact surface to transmit forces directly between said barrier andsaid casing.

3. In a protective system embodying a casing and a barrier pivotallysupported therein for selective projection and retraction, said casinghaving a lower supporting surface for cooperation with a lower edge ofsaid barrier when the latter is in retracted position, the combinationof resilient means for resiliently supporting said barrier within saidcasing including a plurality of buffers distributed along said lowercasing surface, each of said buffers being constructed and arranged toresiliently support a forward edge of said barrier and to provide apositive abutment to limit downward movement of said barrier within saidcasing.

4. In a protective device, a barrier, means for supporting said barrierfor movement between retracted and projected positions, means includingone or more springs connected between said barrier and said support forcontinuously urging and effective to move said barrier to a projectedposition, and means including a drive shaft c0nnected to said barrierfor moving said barrier from a projected position to a retractedposition and for retaining said barrier in said retracted positionagainst the force of said springs.

5. In a protective system, a barrier, means including a casing forsupporting said barrier for movement between a retracted and a projectedposition, continuously acting means including a spring connected betweensaid barrier and said casing for urging said barrier to the projectedposition, a crankshaft, means connecting crankshaft to said barrier,said crankshaft serving to retract said barrier to the retractedposition against the force of said continuously acting means, and meansfor locking said crankshaft in a position corresponding to the retractedposition of said barrier.

6. In a protective system, a barrier, means for supporting said barrierformovement between a projected and a retracted position, continuouslyacting means for urging said barrier to the pro-

